Alfred napier ford



Lil

. the manufacture of insulating compositions UNITED STATES PATENT OFFICE.

ALFRED NAPIER FORD, OF LoNDoN, ENGLAND.

PROCESS OF MANUFACTURING INSULATING COMPOSITIONS FOR ELECTRICAL PURPOSES.

SBECIFIGA'IION forming part of Letters Patent No. 530,517, dated December 11 1894.

Application filed June 11, 1894. Serial No. 514,248. (No specimens.) Patented in England July 17, 1890, No. 11,130.

ing at London, England, have invented oertain new and useful Improvements in Processes of Manufacturing Insulating Compositions for Electrical Purposes, (patented in Great Britain July 17, 1890, No. 11,130;) and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in for electrical purposes, and has for its object, the economy of gutta percha and such like expensive materials.

In carrying out the invention, I effect the,

coating or saturating of certain fibrous and other substances with a drying oilpreferably linseed oil,which has been previously partially oxidized by heating up to 350 Fahrenheit, more or less, for'some hours with litharge or other suitable oxidizing agent, and then drying such fibrous substances so treated, by air,heated or otherwiseand when so dried, recoating them again and again, each time drying the one previous coat sufficiently to take another, until they have increased in weight by means of such coatin g or saturation at least fifty to two hundred per cent., more orless; and after such matter so treated has become finally dry by the oxidation of the oil, I submit the same to the action of grinding or amalgamating rolls,

preferably running at a high speed, until a smooth and homogeneous mass is obtained; and having attained this consistency, I add a suitable proportion, say twenty-five per cent.,of gutta percha, or india rubber, or compositions of the same, and then I subject to the action of crushing or amalgamating rolls, or analogous means of mixing, until it is ca-' pable of being formed into a block, or rolled out into thin sheets.

The fibrous substances I employ may be wood fiber, when it is ready for use by treatment such as described, hemp, flax, jute, cotton, silk or other suitable fiber, sponge, as also worsted,or Woolen, or other suitable animal fiber. This materialis designed to econ0- mize, as stated, the use of gutta percha, or india rubber, or both of them, in use for electrical purposes.

Having thus described myinvention, what I claim is The herein described process for the manufacture of insulating compositions, which process consists, first;-in coating or saturating certain fibrous and other substances with a drying oil which has been previously partially oxidized, and then drying such fibrous substances so treated, and when dry, re-coating them again and again, each time drying the previous coat sufficiently to take another coatuntil the mass has increased in weight by such coating or saturation from fifty to two hundred per cent. approximately, and subjecting the material so treated to the action of grinding oramalgamating rollers, and subsequently adding a quantity of india rubber, gutta percha or similar material, say twenty-five per cent., and finally, subjecting the mass again to'the action of grinding or amalgamating rollers oranalogous means of mixing, substantially as described.

In testimony whereof Iaffix my signature in the presence of two witnesses.

ALFRED. NAPIER FORD. 

